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Volume 29, Issue 9
Displaying 1-15 of 15 articles from this issue
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Masao Homma, Tsuneo Ishida, Katsunobu Yamaya1965 Volume 29 Issue 9 Pages 825-830
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis research was a fundamental analysis of the welding structures of flake graphite and spheroidal graphite cast irons to investigate the change of the graphite structure at the fusion bead, and to prevent flake graphite from being tranformed into eutectic graphite and spheroidal graphite from being collapsed. The heat-cycle was applied to the whole parts of samples in conformity with gas-welding, without the welding procedure.
The results are as follows:
(1) In the flake graphite cast iron, the amount of eutectic graphite increases with the increase of the maximum fusion temperature in air and in contact with the non-reducing flux. However, in the case of reducing fluxes, eutectic graphite hardly increases. Especially, when the amount of FeSi in the reducing flux is increased, a flake graphite similar to that of the original base metal is maintained. In the welding of cast iron, therefore, it is important to cover the fusion bead with the reducing and graphitizing flux during heat-cycle in order to prevent the formation of eutectic graphite which reduces the mechanical properties.
(2) During the welding of the spheroidal graphite cast iron, it is difficult to maintain the spheroidal graphite structure by covering the fusion bead with spheroidizing flux during the fusion period. However, it is possible to restore the original structure by treating it with the spherodizing flux just before cooling down, whatever heating and fusion may be carried out in air.View full abstractDownload PDF (1017K) -
Akio Yamaguchi, Joichiro Moriyama1965 Volume 29 Issue 9 Pages 831-835
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe H2 reduction of single crystals (<80 mesh) of NiO were studied for the purpose of investigating the reaction kinetics and detecting the dependence of reduction rate over the temperature range (220°∼290°C) by means of Delmon’s interruption method. The time dependence of reduction can be described by the equation 1−(1−x)1⁄3=kt, where x is fraction of reduction, t is time, k is rate constant and k was found to be approximately in inverse proportion to particle radii. In view of the above result, it seemed most reasonable to assume that the reduction of each particle started independently with a same probability and then proceeded identically. From the experiment of the annealed NiO single crystals the lack of uniformity in crystals was considered to influence the accelaration of the reduction rate. The value of activation energies of reduction (30.0 kcal/mol) of single crystales (325∼400 mesh) agreed approximately with those of NiO powder prepared from carbonate, hydroxide and nitrate (31.2, 30.5 and 31.6 kcal/mol, respectively).View full abstractDownload PDF (627K) -
Takashi Sakaki1965 Volume 29 Issue 9 Pages 835-842
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis experiment was carried out on the spectrophotometric method with stilbazo, in order to establish a simple and accurate method for the determination of the tin content in iron and steel.
The tin (IV) reacts with stilbazo in an acetic acid-sodium acetate medium to give a complex which shows an absorption maximum at the wave length of 505 milli microns. This complex is stable for 30 min. At the wave length of 505 milli microns, the relation between the amounts of tin and the absorption follows Beer’s law in the range from 0 to 100γ⁄100 mL of tin. The absorption of this complex is constant at pH 5.0∼6.0, when absorption was measured against a blank solution. In this method, there is no significant effect even in case 2 mg each of iron, chromium and beryllium, 5 mg each of manganese, nickel and cobalt, 0.2 mg each of copper and bismuth, 1 mg each of arsenic and lead are contained in the separated sample solution. Alminium, antimony, molybdenum, niobium, tantalum, titanium tungsten, vanadium and zirconium interfere.
The tin was separated from various elements by co-precipitation of the tin with beryllium hydroxide in an ammonical solution containing EDTA, and precipitation as the tin-thionalide complex in a sulfric acid solution containing tartaric acid.
As a result of the experiment, the author succeeded to establish a method in which less than 0.1% of tin in iron and steel can be measured easily and accurately. The tin content in actual samples was measured by this method with satisfactory results.View full abstractDownload PDF (953K) -
Sakae Takeuchi, Tsuneo Homma1965 Volume 29 Issue 9 Pages 843-849
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTo study the mechanism of high temperature fatigue in pure metals, an apparatus containing a microscopic cine-camera combined with a fatigue machine was devised for the continuous and direct observation of the specimen surface during fatigue in vacuum at elevated temperatures. A xenon flash tube was used for illuminating the specimen surface. It was triggered synchronizingly at the same phase of deformation of the specimen. The fatigue process was taken in pictures at the time-lapse sequences and also in the continuous pictures in some cases.
The time-lapse technique was effective for the purpose of analyzing the fatigue mechanism at elevated temperatures. The results obtained in the specimens of pure Al and Pb under reversed bending and torsional stress over the temperature range from 0.5 to 0.85 Tm°K are as follows:
(1) The grain boundaries move in a way that they are parallel to the directions of the maximum shear stress of the specimen axis. Accordingly, boundary faces of polycrystals are gradually aligned to be orthogonal with the directions of the maximum shear stress during fatigue.
(2) Subgrains generate in coarsed grains or in single crystals under reversed stress and their boundary faces are aligned to be orthogonal as in the above case.
(3) The surface markings consisting of a series of sharp valleys and peaks due to the deformation band are found for the specimen under reversed bending at the range of about 0.5 Tm°K.
(4) These continuous observation for the fatigue process supports the suggested mechanism of high temperature fatigue which has been described in the previous reports(1)∼(4).View full abstractDownload PDF (1174K) -
Takashi Shimanuki1965 Volume 29 Issue 9 Pages 850-854
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the determination of phosphorous in ferromolybdenum, a modified molybdenum blue method which used molybdenum in the sample as the reagent was tried. For this purpose, analytical conditions of the molybdenum blue method were experimented, and then the determination method was established.
The procedure which used 4∼5 mL of hydrazine sulfate (0.15%) as the reducing agent and digested in boiling water for 20 min was fitted for the reducing condition of phosphomolybdic acid. The relation between sulfuric acid (N) and molybdenum (mg) was as follows:
H2SO4(N)=K ×Mo (mg)^K’, K=a ∼b.
K and K′ are constants which depend the reducing condition. The range (a∼b) of K shows the range of molybdenum in which a constant absorption takes place at a constant acid concentration. In the reducing condition of this experiment, K was 0.0234∼0.0395 and K′ was 0.78. For example, if 7 mL of 10N sulfuric acid and 90 mL of the total solution, the absorption was constant between 50 mg and 85 mg molybdenum: 50∼85% ferromolybdenum can be determined when 0.1 g of the sample is taken. The amounts of the solution at the digested time scarecely effected. After the sample was dissolved, the acid concentration was adjusted by adding a small amount of sulfuric acid and evaporated to dryness. Then ferric ion was reduced with sodium bisulfide at the acid concentration higher than that of the color developed time in order to prevent the reduction of molybdenum itself. Even in case ferric ion and phosphomolydic acid were reduced at the same time with hydrazine sulfate, satisfactory results were obtained.View full abstractDownload PDF (680K) -
Takashi Shimanuki1965 Volume 29 Issue 9 Pages 855-859
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPhosphorous in ferrochromium was determined without separation of chromium by the molybdenum blue method. Following the preceding report on effects of reagents on the color development, effects of chromium and a few of salts or acids on the color development were further investigated. Effects of co-existing elements, salts and acids, were mainly to retard the rate of color development. Above all, chromium (III) had a remarkable effect. As a result of experiments on the color development in detail, it was found that the effect of chromium (III) could be eliminated when the concentration of reagents was increased and the digestion time was prolonged. In like manner, the effect of acids could also be eliminated. Chromium (III) showed almost no absorption at the wavelength of over 750 mμ.
In this experiment, a reagent mixture solution of 12 mL of 2% ammonium molybdate, 13 mL of 10N sulfuric acid and 5 mL of o.15% hydrazine sulfate was used, and digested at the total volume of about 90 mL for 30 minutes. Chromium (III), amounting up to 150 mg, had no effect in this condition.
This wethod was expedient and its accuracy was equivalent to or higher than that when chromium was separated.View full abstractDownload PDF (788K) -
Yûnoshin Imai, Tsuyoshi Masumoto, Keikichi Maeda1965 Volume 29 Issue 9 Pages 860-866
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe microstructures and the characteristics of precipitated nitrides in various alloys of the Fe-Cr-N system in the range 0.5 to 40% chromium with up to about 1% nitrogen have been studied by optical and electron microscopy and by X-ray diffraction and chemical analysis of the extracted residue. The results are summarized as follows: (1) The nitrides detected in the present work were Fe4N, CrN and Cr2N. (2) In the case of about 0.1%N, the changes in microstructure of the Fe-Cr-N alloys with a lowering of temperature became as follows:
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\ oindent(3) In the case of alloys containing chromium above about 13%, the nitrogen content to obtain a completely austenitic structure increased with the chromium content. The nitrogen contents for 13, 18 and 16%Cr alloys were about 0.1, 0.4 and 0.8%N, respectively. The microstructures of these alloys revealed such a change as γ→γ+Cr2N→α+γ+Cr2N→α+Cr2N. (4) The very fine acicular phase was observed within ferrite in the Fe-Cr-N alloys containing chromium above about 15%, which were quenched in water from above about 1100°C. It was confirmed that this phase is of Cr2N precipitated during cooling due to a remarkable decrease of the solubility of nitrogen in ferrite and the suppression of this precipitation is very difficult.View full abstractDownload PDF (1607K) -
Yûnoshin Imai, Tsuyoshi Masumoto, Keikichi Maeda1965 Volume 29 Issue 9 Pages 866-871
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the present work, the isothermal structural diagrams of the Fe-Cr-N system in the range of compositions between 0 to 40% chromium and up to 1% nitrogen were constructed at various temperatures below 1300°C in accordance with the results of a previous work. From the considerations on the transition of phases and the tranformation planes, the structural diagrams were also obtained with various cross-sections of 0.1% nitrogen, and 13, 18% and 26% chromium. In the ternary Fe-Cr-N system, the existence of the following three invariant reactions was pressumed: (1) L+α\ ightleftarrowsγ+Cr2N above 1300°C, (2) γ+Cr2N\ ightleftarrowsα+CrN about at 790°C and (3) γ+CrN\ ightleftarrowsα+Fe4N about at 760°C.View full abstractDownload PDF (1445K) -
Hisayoshi Maeda, Yoshihito Endo, Tatsunari \={O}kata1965 Volume 29 Issue 9 Pages 871-875
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWir haben schon geschrieben, dass die Härtbarkeit des Schmiede-Härtungsstahls durch das verhältnismässig grobe Austenitkorn zusammenfassend zunahm. Nachdem hierauf bei der Schmiede-Härtung die Einflüsse durch Warmverformung wesentlich sowohl auf das Umwandlungsverhalten in der Perlitstufe als auch auf die Abkühlungsgeschwindigkeit bei der Ölhärtung untersucht worden sind, wurden folgende Ergebnisse im Anschluss an die vorweggenommene Untersuchung geführt:
(1) Mit wachsendem Austenitkorn verringert sich die umwandlungsgeschwindigkeit, und zwar wird der geradmässige Zusammenhang zwischen der kürzesten Zeit für das Ende der Perlitstufenumwandlung und der Kennzahl der Austenitkorngrösse festgestellt.
(2) Da sich die Austenitkorngrosse mit dem Verlauf der Warmverformung vermindert, soll die Härtbarkeit abnehmen zwar wesentlich, dennoch ist dieses Korn gröber als das bei der ordentlichen Härtung zu findende Korn.
(3) Die Abkühlungsgeschwindigkeit bei der zunderfreien Schmiede-Härtung ist um rd. 32% schneller als die bei der ordentlichen Härtung.
(4) Die Härtbarkeit des Schmiede-Härtungsstahls nimmt umfassend durch die Wechselwirkung der verhältnismässig gewachsenen Austenitkorngrösse mit der Abkühlungsgeschwindigkeit zu.View full abstractDownload PDF (478K) -
Hidehiro Goto, Minoru Hosoya, Yoshihisa Otaka1965 Volume 29 Issue 9 Pages 876-881
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe argon carrier hot extraction method for the determination of hydrogen in metals previously reported (J. Japan Inst. Metals, 28 (1964), 764.) was applied to aluminium with satisfactory results. Sufficient sensitivity was attained by using an oil manometer as the detector. The sample was scraped with an ordinary lathe in a dry condition and heated to 600°C in a stream of purified argon to extract hydrogen. The hydrogen extracted was filtered through a palladium tube at 550°C and determined manometrically. Through this palladium tube, even 10∼20 μL of hydrogen could be filtered quantitatively. The extraction time was about 1 hr and the shape of the extraction curve resembles that obtained by hot extraction in vacuo. Surface gas was determined by re-turning the degassed sample followed by extraction. It was found that the amount of surface gas was dependent not only upon the smoothness but freshness of the surface of sample. Coefficients of variation of the internal gas (the mean value of which was 0.36 NmL/100 g) and the surface gas (the mean value of which was 3.2×10−4 NmL/cm2) of 99.9% aluminium were 7.8% and 11% respectively.View full abstractDownload PDF (718K) -
Jitsuhiko Ueda, Isao Hando1965 Volume 29 Issue 9 Pages 881-885
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFatigue tests, micro-and fractographic observations were carried out to investigate the relationship between fatigue strength and microscopic structures in two Al-Si alloys; one had a needle shape Si structure and the other had spherical Si. The results obtained are summarized as follows:
(1) The tensile strength of the needle Si alloy was higher than that of the spherical Si, alloy but the fatigue strength of the former was lower.
(2) Microscopic observations of the specimen surface showed that fatigue cracks propagated mainly along Si in all the specimens.
(3) The fractographic observation showed fatigue striations and a river pattern.View full abstractDownload PDF (845K) -
Takao Kimura, Yasushi Watanabe1965 Volume 29 Issue 9 Pages 885-890
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA series of dilute solid solutions of Cu containing Be up to 0.80 wt% in the form of a cylinder or plate were internally oxidized at temparatures between 600° and 1000°C to investigate the growth and structures of the subscale formed.
The results obtained are as follows.
(1) The relationship between the penetration depth and the oxidation time of the cylindrical specimen is well expressed by the equation derived by Meijering.
(2) Owing to the presence of the fine BeO particles in the Cu matrix, the diffusion of the oxygen is enhanced. With incresse of the BeO content, the diffusion coefficient of the oxygen also increases.
(3) Grain boundary diffusion prevails at the lower internal oxidation temperature. This effect is particularly large as the concentration of the solute element increases.
(4) The size of the BeO particles increases with the penetration depth in the plate specimen.View full abstractDownload PDF (833K) -
Shigeo Horiuchi, Tadatsune Okubo, Isao Gokyu1965 Volume 29 Issue 9 Pages 891-898
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA process of the formation of cube recrystallization texture in a heavily cold rolled copper sheet was examined mainly by using a transmission electron microscope technique, and the following characteristic findings were observed. (1) At the early stage of annealing, small recrystallized grains of more than about 1μ in diameter, with cube orientation, suddenly appear in the deformed matrix and contain annealing twins. (2) They are arranged in straight rows parallel to R.D., at each side of which crystal orientations differ. (3) Recrystallization does not occur preferentially in the region with cube orientation which has been formed during rolling. (4) The deformed matrix is slowly recovered and polygonized. Polygons slowly grow, but rarely become larger than 3μ in diameter. Recrystallized grains with cube orientation rapidly grow at the expense of the recovering deformed matrix.
From these observations, it seems reasonable to think that cube recrystallization nuclei would be formed due to inverse Rowland transformation near the boundary between {112}⟨111⟩ twin components and also the simultaneous recovery of defects formed at the boundary during the rolling.
It was clarified in a previous paper(1) that {112}⟨111⟩ twin components could be obtained during rolling by slip rotations in the reverse direction, therefore, if the nuclei are assumed to be formed only when the components are just in the twin relationship, the fact that the spread of the cube texture is extremely small can be explained.
Recovery in the deformed matrix takes place by the decrease in the density of dislocations due to the unification of unlike ones and annihilation, and further polygonizations due to the rearrangement. Finally, a model of formation of cube texture is given.View full abstractDownload PDF (1414K) -
Michitomo Katô1965 Volume 29 Issue 9 Pages 898-902
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe behavior of the grain boundary deformed in shearing at a constant load and temperature was studied by the use of a bicrystal specimen of high purity aluminum. The bicrystal has been prepared by the recrystallization method. The proceeding behavior of grain boundary slip was stepwise in the constant loading test, and it was discontinuous at high temperature in the constant heating test.
The process of shearing at the grain boundary can be classified into two groups due to (1) the crystal flow in the adjacent zone of the boundary and (2) the plastic phenomenon of grain bouodary itself. The grain boundary migration showed the same appearance as that in the case of a high temperature plastic deformation, and it developed in a part of the adjacent zone of the boundary migration was not constant; in some case, when a part of the boundary migrated in a certain direction, the remaining part migrated in the reverse direction.View full abstractDownload PDF (856K) -
Seita Sakui, Tsutomu Kakuma, Tsutomu Mori1965 Volume 29 Issue 9 Pages 903-908
Published: 1965
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFor the purpose of studying the behaviour of aluminum under dynamic loading, single crystals with several orientations were deformed at room temperature and −196°C with the impact tensile machine and the results were compared with those in static tests. Stress-strain curves thus obtained showed clearly the dependence on both temperature and strain rate. The difference in the stress-strain diagrams of dynamic and static tests at room temperature was partly due to the difference in deformation history, i.e., the work hardening process and partly to the strain rate dependence of flow stress itself. At −196°C, however, for the specimens with some orientation, it was entirely due to the strain rate dependence of flow stress itself. Moreover, the slip band observation also revealed the fact that work hardening process in the dynamic test differs from that in the static test. This conclusion was confirmed by observations on the dislocation arrangements with a transmission electron microscopy and with X-ray diffraction photographs.View full abstractDownload PDF (1032K)
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